torious Montrose. At the head of four thousand horse he, on 6 Sept., entered Scotland by Berwick, where he had an interview with the fugitive committee of estates. His original design was to intercept Montrose at the Forth, but learning at Prestonpans that he was still in the south of Scotland, he resolved to attack him there. He was favoured of fortune, but this scarcely lessens the merit of his achievement. By a rapid march southward he surprised Montrose in the early morning of 13 Sept. while the low grounds of Philiphaugh, on which Montrose had encamped, were enveloped in mist, and almost annihilated his forces, Montrose himself, with a few horse, escaping to the mountains. The glory of the victory was sullied by the massacre of the camp-followers, including a large number of Irish women. This apparently was done in retribution for excesses committed by Montrose. After his victory Leslie advanced northwards to the Lothians, and thence convoyed the committee of estates to Glasgow, where his services were rewarded with a gift of 50,000 merks and a chain of gold (Guthry, Memoirs, p. 205). He then proceeded to Angus, and for a time made Forfar his headquarters; but when it was discovered that Montrose was no longer dangerous he returned to England, and rejoined the Scots army under Leven at Newark-upon-Trent.
After the surrender of the king to the English in January 1647, the Scots army returned home. It was reduced to six thousand, and, under the command of Leslie with the rank of lieutenant-general, was sent to the north of Scotland to extinguish the embers of insurrection there. After capturing the castles of the Gordons, and chasing Huntly and his followers to their highland fastnesses (Turner, Memoirs, p. 44), Leslie passed into Argyllshire, whence he drove the Macdonalds and their Irish allies out of Scotland (ib. p. 46; Guthry, p. 243; Baillie, iii. 6). The garrison of one stronghold which had made a strenuous resistance were massacred without mercy after their surrender. In 1648 Leslie was offered the command of the horse in the army of the ‘Engagers’ for the rescue of the king; but, like the Earl of Leven, he declined to serve on account of the disapproval of the kirk authorities. After the defeat of the ‘Engagers’ at Preston Leslie took part in modelling the ‘Whigamores’ as an organised force in support of Oliver Cromwell. The alliance with Cromwell was severed by the execution of Charles I, but the Whigamores only gave a conditional support to Charles II. When Montrose made his appearance in the north of Scotland to effect the restoration of Charles II as an uncovenanted king, Leslie was despatched against him with a large force. As usual, his movements were characterised by great expedition; and in order still further to limit the opportunities of Montrose to collect followers, he sent forward a detachment under Colonel Strachan, which on 27 April totally routed the enemy at Invercarron. Montrose made his escape, but through Macleod of Assynt he was delivered up to Leslie, who conducted him in an ignominious manner to Edinburgh, where he suffered execution.
When Charles II agreed to mount the throne of Scotland as a covenanted king, Leslie became the real commander of the army raised on his behalf, as depute for the old and infirm Earl of Leven. To deal with the emergency Cromwell deemed it necessary to return from Ireland and conduct an invading force into Scotland. Leslie, on the enemy's approach, made no attempt to hold the south of Scotland, but devastated the open country between Berwick and Edinburgh. Outside Edinburgh he awaited Cromwell's arrival behind a line of defence selected and fortified with such skill that it was practically impregnable. Finding it equally impossible to cut off his supplies or entice him from his lines of defence, Cromwell was ultimately compelled from lack of provisions to withdraw to Dunbar. Keeping the high grounds to the west, Leslie closely attended his retreat, and while pushing forward a detachment to seize the pass of Cockburnspath, and to thus cut off his escape to England, drew up the main body of his forces on the slopes of the Lammermuirs. Cromwell was undoubtedly outmanœuvred. He himself practically acknowledged that his case was desperate. It has been generally supposed that, had Leslie been left to his uncontrolled judgment, he would have maintained his attitude of masterly inactivity. For this the chief direct evidence is the statement of Burnet that Leslie told the committee of estates that by ‘lying there all was sure, but that by engaging with gallant and desperate men all might be lost’ (Own Time, ed. 1839, p. 36). Leslie also declined to accept responsibility for the defeat on the ground that he ‘had not the absolute command’ (letter in Thurloe, i. 69); but he nevertheless attributed his defeat simply to the failure of his men, after moving down from the hills, to stand to their arms during the night, and of the officers to stay by their troops and regiments (letter quoted from Lothian Papers in Burton, Hist. of Scotland, vii. 26). He also affirms that, had they followed his counsel, Cromwell would have
